Extra Security that's simple and easy to fit! Sash Blockers are designed to provide additional security for your uPVC doors and windows. They are easy to fit and easy to operate too- just a twist of the Jammer Arm will lock or release the sash. High quality cast zinc construction Durable die cast finish in White. Recommended by insurance companies. Easy to use- just 5 minutes! Easy to use- just flick on and off! Versatile- can be used on numerous windows& doors., Manufacturer: Prettyui